Mersenne: prime95 fans slaying cpus
Steve As far as laptops are concerned, while running Prime95 or fermat.c on my former 233MHz Acer laptop it used to overheat, sometimes so severely, that the bottom of the case was uncomfortable to the touch. The problem was completely resolved by using a PCMCIA Notebook cooling fan when running my laptop 24/7 like a desktop. The fan unit slid into and was powered by the lower of my two PCMCIA slots. While running Prime95 with the fan running the case was barely warm to the touch. These PCMCIA fans used to cost around $35 from Micro Center or CompUSA. Regards Alan Powell _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: slaying cpus with prime95
As for SMART on disks - I've never heard of SMART giving more than 24 hours notice of a failing disk, but I have heard of many cases where disks have died without prior warning even though SMART monitoring has been active. Other people seem to have the same experience. I get the impression that SMART monitoring may be a waste of (a relatively small number of) CPU cycles. I guess experiences will vary. I know that on our Compaq servers, the SMART warnings are wonderful. Just recently I swapped out a drive that was giving off warnings about too many sectors having to be remapped. And in the case of Compaq servers, if you're using all the Insight Manager agents, a drive is covered under warranty *before* it's even failed (that good old pre-failure warranty), so you can swap it out even though technically it's still working okay. I've done that several times on Compaq systems, and I think it's wonderful. But I guess it all depends on the monitoring software in place. All SMART is going to tell you is the # of errors and other drive indicators, and I guess it's up to the software to determine if those errors constitute normal behaviour or if there's something more serious involved. Same goes with the CPU and fan monitoring... those Compaq systems monitor fan rotation, temperatures at multiple points inside the case, etc. There are pre-defined settings for those sensors, so that if the temperature goes above, you can either have the system shut down or keep on running but send an alert (on a server, it's preferable to have it send an alert, otherwise having a system shut down without any notice can be aggravating, but I guess that's a matter of whether or not you have 24/7 human monitoring of alerts, so you can react quickly to those). Granted, Compaq servers with all those features cost a pretty penny. Their desktops offer most of the same things, albeit not as many sensors inside the case. :) I think I've mentioned this before, but it is interesting to see how when I kick off Prime95 on one of those servers, the fans which normally are just idling will kick into high gear. They're variable speed, so they only kick in when needed, and it doesn't take long at all for the CPU's to heat up and trigger the extra fan rpm's. On a lot of the newest Compaq servers, you can put in redundant fans so if one or two fail, you're still covered, and you also get better cooling when all are running. Granted, these things can be QUITE loud (I have 3 on my desk right now and it is annoying, but thank goodness they're just the slim DL360's). The huge cluster boxes or 8-way servers can deafen a person, not to mention the Storageworks boxes with those monstrous vortex fans on the back, pumping who knows how many CFM's and generating quite a few decibels in the process. :) Aaron _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: variable iteration speeds
On an otherwise idle Linux system, I've been noticing that the per-iteration speed has been varying during the course of a single primality test. Until Saturday afternoon I'd been getting a fairly consistent 0.188/0.189s time when the system was idle. It then increased to around 0.206s. It fell again last night to around 0.199s (see logs below - percentages trimmed for 80-character neatness). Any ideas? It's a Duron 700 desktop system with 512MB PC133 RAM. All I can think of is that something is having a small but noticeable affect on memory access speeds. I can't think of anything I've changed over the past few days on the system: kernel, libraries, etc are all the same. Not a major problem, I'm just curious :-) [Jan 12 02:52] Iteration: 475 / 13355561 Per iteration time: 0.190 sec. [Jan 12 05:29] Iteration: 480 / 13355561 Per iteration time: 0.189 sec. [Jan 12 08:07] Iteration: 485 / 13355561 Per iteration time: 0.189 sec. [Jan 12 10:48] Iteration: 490 / 13355561 Per iteration time: 0.193 sec. [Jan 12 13:34] Iteration: 495 / 13355561 Per iteration time: 0.199 sec. [Jan 12 16:26] Iteration: 500 / 13355561 Per iteration time: 0.207 sec. [Jan 12 19:20] Iteration: 505 / 13355561 Per iteration time: 0.208 sec. [Jan 12 22:13] Iteration: 510 / 13355561 Per iteration time: 0.208 sec. [Jan 13 01:07] Iteration: 515 / 13355561 Per iteration time: 0.208 sec. [Jan 14 11:05] Iteration: 575 / 13355561 Per iteration time: 0.199 sec. [Jan 14 13:51] Iteration: 580 / 13355561 Per iteration time: 0.199 sec. [Jan 14 16:37] Iteration: 585 / 13355561 Per iteration time: 0.199 sec. [Jan 14 19:24] Iteration: 590 / 13355561 Per iteration time: 0.200 sec. [Jan 14 22:11] Iteration: 595 / 13355561 Per iteration time: 0.200 sec. [Jan 15 00:53] Iteration: 600 / 13355561 Per iteration time: 0.194 sec. [Jan 15 03:35] Iteration: 605 / 13355561 Per iteration time: 0.194 sec. [Jan 15 06:16] Iteration: 610 / 13355561 Per iteration time: 0.194 sec. -- --- Robin Stevens [EMAIL PROTECTED] - Oxford University Computing Services --- Web: http://www.cynic.org.uk/ --- (+44)(0)1865: 273212 (work) 273275 (fax) Mobile: 07776 235326 --- _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: just some comments to improve our site
Why is P-1 factoring not a single schedule task? like the LL and the Trail Factoring? Why is P1 factoring hooked upon the LL test? Why does P1 not have it's own life like the TF and the LL? I realy hated the P1 until now 21.4 fixed that. And I hated the CPU-clocks of earlier versions to, because I have no idea what so ever the clock beat of my computer is, but I can relate to time. Some people might have plenty of mem - outdoing my best a 512M - but some of the machines I (or maybe Primenet) have selected for P-1 have nothing more than 64 or 128M. We also need a a place for rapid starters. Some Gazelle view. Wow! Even though I've only done 0,323 P90 years I'm number 33 in this week I will certainly continue, because I will catch up with those guys having 79 years Hmmm, maybe in percentage of the week before. Also the newsletter should more often be sent. We make progress every day so why don't we tell GIMPS'ers what is happening? Even a small progress is a giant leap, like now all numbers below 4.900.000 has been doublechecked or All numbers below 16.000.000 has been trial factorized. Just my few words happy hunting tsc _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Factors
I have downloaded the factor files suggested by GIMPS but it gives no meaning. How do I read the files *.cmp? And why is this not documented close to the source of the *.cmp files? I am also a bit disannoyed about numbers less than M751 that should be fully factorized seems unavaible, or am I looking the wrong places? Do you know a site which I don't? I'd also like to know about any number fully factorized, whatever size it might be, and whatever size the factor(s) might be. The next step for GIMPS is a faster factoring algorithm and the way to get that will be that someone - maybe a mathematician or some beer-drinking fool like me - finds the stones of immortality. :-) Besides I have the question: why does the advanced facor algortithm of prime95 somtimes find 2 factors? This happens eg. at M1289, has 108817410937 and 15856636079 as factors? Happy hunting tsc _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Factors
Hi, At 11:59 PM 1/15/2002 +0100, =?utf-8?Q?Torben_Schl=C3=BCntz?= wrote: I have downloaded the factor files suggested by GIMPS but it gives no meaning. How do I read the files *.cmp? From the status.htm web page: You will need a special program to decompress the known factors data The special program is: ftp://mersenne.org/gimps/decomp.zip I am also a bit annoyed about numbers less than M751 that should be fully factorized seems unavaible, or am I looking the wrong places? Do you know a site which I don't? Go to the Cunningham project at: http://www.cerias.purdue.edu/homes/ssw/cun/index.html The next step for GIMPS is a faster factoring algorithm and the way to get that will be that someone - maybe a mathematician or some beer-drinking fool like me - finds the stones of immortality. :-) Good luck finding this algorithm. Many advances have been made the last two decades. We eagerly await the next one! Besides I have the question: why does the advanced facor algortithm of prime95 somtimes find 2 factors? This happens eg. at M1289, has 108817410937 and 15856636079 as factors? I don't remember. That code is no longer supported. Best regards, George _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: just some comments to improve our site
- Original Message - From: Torben Schlüntz [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Tuesday, January 15, 2002 10:26 PM Subject: Mersenne: just some comments to improve our site Why is P-1 factoring not a single schedule task? like the LL and the Trail Factoring? Why is P1 factoring hooked upon the LL test? Why does P1 not have it's own life like the TF and the LL? This has been discussed at length. The problem is that it is difficult to get the server code changed. [...] Some people might have plenty of mem - outdoing my best a 512M - but some of the machines I (or maybe Primenet) have selected for P-1 have nothing more than 64 or 128M. If you have several machines, with different amounts of available RAM, then you could perhaps give P-1 work of the other machines to the one with the greatest. That would involve some manual labour. Also the newsletter should more often be sent. We make progress every day so why don't we tell GIMPS'ers what is happening? Even a small progress is a giant leap, like now all numbers below 4.900.000 has been doublechecked or All numbers below 16.000.000 has been trial factorized. Have we sent a newletter since finding M#39? Just my few words happy hunting tsc Daran _ Unsubscribe list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
